Continuation power flow based on a novel local geometric parameterisation approach

Continuation power flow based on global parameterisations cannot overcome the Jacobian matrix singularity for some voltage instability cases with strong local characteristics and local parameterisation methods may need a forced parameter-switching strategy at the lower part of P-V curve and a special step-length tuning algorithm. The upper part of P-V curve can be solved through conventional newton power flow easily with load factor as parameterisation variable. Therefore this study focuses on tracing the segment near the saddle-node bifurcation (SNB) point and the lower part of P-V curve. A new local geometric parameterisation technique is proposed, which can trace P-V curve with a fixed step-length of parameterisation variable and no parameter-switching strategy is needed in most cases. The Jacobian matrix singularity near the SNB is avoided by the addition of a linear equation, which is determined from the selected bus voltage magnitude and the loading factor. The method to deal with limit-induced bifurcation problems is also considered in this study.